of an ideal linear sensor in the absence of noise is defined as , whereas for nonlinear sensors it is defined as the local slope . In the absence of noise and signals at the input, the sensor is assumed to generate a constant intrinsic output noise . To reach a specified signal to noise ratio at the output , one combines these equations and obtains the following idealized equation for its sensitivity , which is equal to the value of the input signal that results in the specified signal-to-noise ratio at the output:

This equation shows